The present invention relates to a process for manufacturing a bearing seat for a half-shell bearing provided in a metal part. A preferred, although not exclusive, use of the process according to the invention, is the manufacturing of a bearing seat for a half-shell bearing arranged in the application device of a disk brake.
In a known process of this type, a bore is formed in the metal part in which the bearing seat is to be manufactured, first by boring or turning along the axis of the bearing seat. The diameter of this bore corresponds approximately to that of the bearing seat. Then the metal part is worked by a milling tool or by a saw in such a manner that the desired bearing seat is exposed as one half of the bore. This known process requires comparatively high expenditures and, furthermore, has the disadvantage that, because of the bore, at least one of the two axial faces of the bearing seat is open. This is undesirable in many cases. Thus, for example, when the bearing seat for a half-shell bearing is used in the application device of a disk brake, the bearing is arranged in the rearward housing portion. An additional sealing for the bore hole has to be provided in order to ensure the tightness of the housing.
In the case of another known process, the bearing seat for the half-shell bearing is produced directly by milling or grinding. In this case, it is possible to keep both axial faces of the bearing seat closed. However, this process requires comparatively high-expenditure processing steps and therefore increases the manufacturing costs considerably. In many cases, this process cannot be used because the space is not sufficient in the housing portion of an application device, for a stable accommodation of the milling or grinding tool.
It is an object of the invention to provide a manufacturing process which is distinguished by low costs and can be carried out without any problems even in narrow spaces.
According to the invention, this object is achieved by the following process steps. The bearing seat is formed in and at the same time of the manufacture of concerned metal part by a forging or casting operation. A half-shell-shaped recess is formed whose diameter is slightly smaller than that of the half-shell bearing. Subsequently, the recess is subjected machined by a non-cutting process until the diameter of the recess corresponds to that of the half-shell bearing. The non-cutting forming provided according to the invention requires few expenditures and can therefore be carried out at very low cost. Also, limited space conditions present no problem. Finally, the process according to the invention is also distinguished in that the axial face walls of the bearing seat are not necessarily exposed by a machining process to form the seat as in the prior art. A subsequent lateral sealing of the corresponding metal part is therefore not required.
Surprisingly, it was found that, it is particularly advantageous to provide the surface of the recess with a non-planar profile during the forging or casting operation. In this case, the subsequent non-cutting forming can be carried out at particularly low force. Any damage to the metal as a result of the non-cutting forming is therefore impossible. A further advantage of such a profile is that the precise final dimensions of the bearing seat may be controlled, if required, by the respective shape of the profile, while the operating parameters of the non-cutting forming remain uniform or constant. In addition, it is possible to control the achievable surface quality by dimensioning the depth and/or by the shape of the profile.
The mentioned profile may be constructed, for example, in the form of trapezoid, saw-tooth-shaped or wavy ribs. These may be arranged, for example, in parallel or transversely to the longitudinal axis of the recess. As an alternative, it is also possible to construct the profile in the form of essentially uniformly distributed projections or indentations. If the concerned metal part is produced by a casting operation, the respective profile may be manufactured in a particularly simple manner and almost without any additional machining costs by a corresponding construction of the negative profile in the casting mold.
It was found that the non-cutting forming of the recess according to the invention can take place in a particularly low-cost and comparatively fast manner by stamping or striking. Although no great precision can be achieved by this forming process, it will be sufficient in many cases. However, when a higher precision is required, the forming may be carried out by a so-called "roller burnishing", in which the surface is smoothed out by a roller. It may also be possible to first carry out a rough machining by stamping or striking and then carry out a finishing by roller burnishing until a desired manufacturing tolerance is achieved.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.